I'm working with SD, NTSC video. Granted, I've only been working with the trial version of NV and I love the results. Before I commit to a purchase, I'd like to address some issues that will help me decide which version to purchase:

1. Banding: This occurs in filtered dark scenes (particularly where heavy noise was present). If I purchase the pro version, I assume that NV will temporarily perform a chroma upsampling to a higher bit-depth (32 bits, I think?) before filtering, in order to prevent the banding. Am I correct?

2. Color Splotches: There is a scene where, after NV filtering, I see color splotches. I might be able to post a sample tonight. This occurs in a few frames only and, unless I view each frame individually, the eye can miss it. Is this a bug, a result of using the trial version?

1. Banding may be caused by the host application itself and/or the output codec. To verify that please replace NV with Gaussian Blur in that clip and check the results. It is quite likely that the banding is even stronger then.
Regarding NV Demo vs Pro and different bitdepth, the Pro can indeed work in higher precision than Demo. However, if the banding problem is caused by the host or codec then working in higher precision will likely not help anyway, because the problem is eslewhere. Please try the above test to verify that.

2. I don't think it is a bug or the result of using the Demo. It is most likely a result of incomplete filtration where some noise elements remained unfiltered for some reason. There may be many reasons for that and usually that can be solved by the corresponding adjustments of the filter settings and/or building a better noise profile. For example, if the color splotches are large in size then it may be necessary to enable the Very Low Freq option in NV filter settings (working in Advanced mode, available through menu Tools > Advanced mode).